Master batch elastometer containing organically modified silica and method of preparing the same

Abstract

Provided are an organically modified silica master batch elastomer having superior affinity for silica and a method for preparing the same. A copolymer solution-polymerized from a conjugated diene-based monomer and a vinyl aromatic monomer is mixed in solution with organically modified silica having the silica modified with a specific aliphatic hydrocarbon to prepare the organically modified silica master batch elastomer. The organically modified silica master batch elastomer according to the present invention has improved mechanical properties, abrasion resistance and blending processability over the existing master batch elastomers containing common silica. Thus, when it is used as a tire material, improved fuel efficiency, abrasion resistance and wet traction may be expected.

What is claimed is: 
     
       1. A method for preparing an organically modified silica master batch elastomer, comprising:
 solution polymerizing a conjugated diene monomer with a vinyl aromatic monomer to prepare a copolymer; 
 reacting silica with 1-10 wt % of an organosilane compound represented by Chemical Formula 1 and 1-10 wt % of a silane coupling agent represented by Chemical Formula 2, based on the weight of the silica, to prepare organically surface-modified silica; and 
 mixing 100 parts of the copolymer by weight with 10-150 parts of the organically modified silica by weight in solution phase and then drying to prepare a master batch elastomer:
   R 1 —Si—(OH) 3   (1)
 
 
 wherein R 1  is a C 2 -C 20  aliphatic hydrocarbon group; and
   (EtO) 3 Si(CH 2 ) 1 —(S)—(CH 2 ) m Si(OEt) 3   (2)
 
 
 wherein each of 1 and m is independently an integer from 1 to 5, and n is an integer from 1 to 4. 
 
     
     
       2. The preparation method according to  claim 1 , wherein the organically modified silica is surface-modified with 5-15 wt % of an organic compound comprising the organosilane compound and the silane coupling agent, based on the weight of the silica. 
     
     
       3. The preparation method according to  claim 1 , wherein the compound of Chemical Formula 1 is propyltriethoxysilane. 
     
     
       4. The preparation method according to  claim 1 , wherein the compound of Chemical Formula 2 is bis(triethoxysilylpropyl)tetrasulfide or bis(triethoxysilylpropyl)disulfide. 
     
     
       5. The preparation method according to  claim 1 , wherein the conjugated diene monomer is 1,3-butadiene, isoprene or a mixture thereof. 
     
     
       6. The preparation method according to  claim 1 , wherein the vinyl aromatic monomer is styrene, α-methylstyrene, ethylstyrene, isopropylstyrene, halogenated styrene or a mixture thereof. 
     
     
       7. The preparation method according to  claim 1 , wherein the solution polymerization and the mixing are performed in a solvent selected from cyclohexane, toluene, n-hexane and heptane.